The present invention relates to a gas turbine engine pylon arrangement.
Aircraft powered by gas turbine engines often include a mechanically driven accessory gearbox to drive accessory systems such as fuel pumps, scavenge pumps, electrical generators, hydraulic pumps, etc. The power requirements of the accessory gearbox continue to increase as the number of electrical systems within aircraft increase.
Conventional gas turbine engine accessory gearboxes utilize a separate gearbox case mountable underneath the engine axially near the diffuser case. The accessory gearbox is driven by an angle gearbox axially forward of the accessory gearbox through a layshaft. The angle gearbox is driven by a towershaft driven by the high-pressure spool.
Although effective, one disadvantage of this conventional arrangement is the utilization of a relatively significant amount of space within the engine core nacelle as well as the multiple shaft and gearbox arrangement required to transfer power from the towershaft to the independent accessory gearbox. To accommodate these design conditions, the nacelle design may provide less than optimal performance at cruise conditions.
Accordingly, it is desirable to provide an accessory gearbox for a gas turbine engine which provides power to larger generators than conventional engines, yet facilitates nacelle packaging.